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问题 选择题

某无色气体可能含有CO2、CO、H2中的一种或几种，依次进行以下实验(假设每步反应均完全进行)：

①通过赤热的炭层后，恢复到原状态，气体体积不变；②通过灼热的CuO时，固体变成红色：③通入澄清石灰水中，石灰水变浑浊；④通过白色CuSO4粉末时，粉末变成蓝色晶体(白色CuSO4粉末遇水变蓝色)。下列判断正确的是[ ]

A．原混合气体中一定含有CO2、CO、H2

B．原混合气体中一定含有CO，可能含有H2，一定没有CO2

C．原混合气体中一定含有H2和CO，一定没有CO2

D．原混合气体中一定含有CO，可能含有H2和CO2

答案

答案：B

填空题

单词拼写。根据下列句子及所给汉语注释，在答题纸相应的位置上写出空缺处各单词的正确形式

（每空只写一词）。

1. Failing in the examination again ________ (心烦意乱) her a lot.

2. He looks handsome and gentle, but _________ (实际上) he is a thief.

3. Mr Huang said that he wnted to buy a bigger ________ (公寓) to live in.

4. Look, Tom. Your desk is very ________ (布满灰尘的). Why not clean it right now?

5. Excuse me, Professor Li, can you be ________ (出席) at our meeting tomorrow?

6. She doesn't want to set down a ________ (系列) of facts in a diary as most people do.

7. My uncle suffered from a serious disease. Luckily he has ________ (康复) now.

8. Mrs. Brown always gives me a hand when I am in trouble. I am really ________ (感激) to her.

9. Singapore has a large number of fluent English speakers because its ________ (官方) language is English.

10. Because of the cold, the water _______ (逐渐地) changed into ice.

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单项选择题

调车手信号指挥机车向显示人反方向稍行移动的信号昼间为（）。

A.拢起的红色信号旗直立平举，再用展开的绿色信号旗上下小动

B.拢起的红色信号旗直立平举，再用展开的绿色信号旗左右小动

C.拢起的红色信号旗高举，再用展开的绿色信号旗左右小动

D.拢起的红色信号旗高举，再用展开的绿色信号旗上下小动
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